1. Field of the Invention
Hydrostatic Tester for Plastic Lined Pipe and Fiberglass Pipe.
2. Description of the Prior Art
In the past, steel oil well pipe has been tested hydrostatically by an assembly that includes a pair of longitudinally spaced resilient packers that slidably and sealingly engage the interior surface of a stand of pipe as the latter is lowered into an oil well bore.
The assembly includes laterally spaced movable serrated slips that can be moved into forceful contact with the interior surface of the pipe, and the force exerted thereon being sufficient that the serrations actually penetrate into the metal of the pipe to removably hold the assembly at a fixed position in the pipe.
During the past few years, plastic lined oil well tubing and casing, and fiberglass tubing and casing have become increasingly popular. Such special tubing and casing like all steel tubing must be periodically tested. However, in the testing of plastic lined tubing or fiberglass, slips cannot be used as a part of the hydrostatic tester for the slips when expanded into a holding position in the pipe would penetrate the plastic lining and render the same valueless for protective purposes.
A major object of the present invention is to provide a hydrostatic oil well pipe tester, and method of using the same, in which a string of plastic lined pipe may be hydrostatically tested prior to being lowered into an oil well bore, and the testing carried out without doing damage to the plastic lining or pipe.
Another object of the present invention is to supply an oil well tubing tester that automatically assumes a self-supporting position in a vertical stand of oil well pipe when the upper portion of the tester is moved above the upper extremity of the stand of pipe.
These and other objects and advantages of the invention will become apparent from the following description of a preferred form thereof. Although the hydrostatic oil well pipe tester is particularly adapted for the testing of plastic lined oil well pipe, it may be also used on all metal oil well pipe if desired.